Track-lighting refers to light fixtures that are cable of being attached anywhere along a continuous electrified track; in contrast to lighting that usually requires electrical wiring to each individual light fixture position. Track-lighting has the advantage of being capable of being mounted to a variety of structural surface, such as ceilings, walls, beams and rafters.
Typical track-lighting systems have a line voltage running through a recessed track or power track. The power track may have more than one live conductor, so that multiple switching circuits can be used to control different lights operating from the same power track. Systems often operate with low voltage (10, 12, or 24 volts). In this case, the power track is electrified through a low-voltage transformer. Some newer track-lighting systems use a single live conductor and a suitable digital control interfaces, such as DALI to control each adapter coupled to the track.
There are generally three standard types of power tracks or power track styles that use corresponding power unit adapters referred to as “H”, “J”, and “L” styles. Each of the different types or styles of power tracks requires different corresponding power unit adapters. Power unit adapters, herein, refer to the portion, or portions of a track-light system that couple light engines to a power track.